Investigation into possible causes for continued onchocerciasis high prevalence in the Wenchi municipal area of Ghana

Main Objectives

• To investigate the presence and the extent of ongoing onchocerciasis transmission in Wenchi Municipal area and identify factors which might have contributed to it

Specific objectives:

• To prospect for black fly breeding sites in a 20km radius around Kwanware
• To assess Onchocerca volvulus infections in blackfly populations and human biting rates at or close to the breeding sites during the peak biting season in August
• To assess the prevalence and intensity of onchocerciasis infections in adult population in Kwanware and other communities
• To determine the sero-prevalence of onchocerciasis Ov16 antibodies in children in Kwanware and other neighbouring communities
• To validate the treatment coverage and adherence to ivermectin following the July 2019 MDA and understand the factors that influence them e.g migration

Summary

In 2017 Ghana carried out an impact assessment of its onchocerciasis programme. The findings from that assessment showed that seroprevalence in children less than 10 years ranged between 0 and 5% in most of the surveyed communities. However, one community, Ottu-Kwanware recorded a seroprevalence of 38%, the highest in that study and in recent years. The sample size was, however, too small raising the issue of how widely to interpret this finding. Thus, there is the need to carry out a more thorough investigation to understand the nature of onchocerciasis transmission in the Wenchi municipal area.

The current study employs parasitological and entomological surveys to understand the extent of onchocerciasis transmission in and around Kwanware community. This study will also employ household treatment coverage surveys to understand the reasons for what appears to be sustained transmission in the Wenchi municipal, specifically around Kwanware and neighbouring breeding sites.